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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity leds is
port (clk : in std_logic;
led1, led2, led3, led4, led5 : out std_logic);
end leds;
architecture blink of leds is
signal clk_4hz: std_logic := '0';
constant gates: integer := 3 - 1;
signal max: integer := 3e6;
signal A: std_logic_vector(0 to gates) := ( others => '0');
attribute keep: boolean;
attribute keep of A: signal is true;
signal B: std_logic := '1';
signal C: std_logic := '1';
signal val: std_logic := '0';
signal data: std_logic := '0';
begin
process (clk)
variable counter : unsigned (23 downto 0) := (others => '0');
begin
if rising_edge(clk) then
if counter >= max then
counter := x"000000";
clk_4hz <= not clk_4hz;
else
counter := counter + 1;
end if;
end if;
end process;
GEN:
for i in 0 to gates generate
A(i) <= not A(gates - i);
end generate GEN;
led2 <= clk_4hz;
led3 <= clk_4hz;
led4 <= clk_4hz;
led5 <= clk_4hz;
end;
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